Vejan P, Abdullah R, Khadiran T, Ismail S
Faculty of Science, Institute of Biological Sciences, University of Malaya, Kuala Lumpur, Malaysia.
Faculty of Science, Centre for Research in Biotechnology for Agriculture (CEBAR), Institute of Biological Sciences, University of Malaya, Kuala Lumpur, Malaysia.
Lett Appl Microbiol. 2019 Jan;68(1):56-63. doi: 10.1111/lam.13088. Epub 2018 Nov 22.
Sustainable crop production for a rapidly growing human population is one of the current challenges faced by the agricultural sector. However, many of the chemical agents used in agriculture can be hazardous to humans, non-targeted organism and environment. Plant growth promoting rhizobacteria have demonstrated a role in promoting plant growth and health under various stress conditions including disease. Unfortunately, bacterial viability degrades due to temperature and other environmental factors (Bashan et al., Plant Soil 378: 1-33, 2014). Encapsulation of bacteria into core-shell biopolymers is one of the promising techniques to overcome the problem. This study deals with the encapsulation of Bacillus salmalaya 139SI using simple double coating biopolymer technique which consist of brown rice protein/alginate and 0·5% low molecular weight chitosan of pH 4 and 6. The influence of biopolymer to bacteria mass ratio and the chitosan pH on the encapsulation process, physic-chemical, morphology and bioactivity properties of encapsulated B. salmalaya 139SI have been studied systematically. Based on the analysis of physico-chemical, morphology and bioactivity properties, B. salmalaya 139S1 encapsulated using double coating encapsulation technology has promising viability pre- and postfreeze-drying with excellent encapsulation yields of 99·7 and 89·3% respectively. SIGNIFICANCE AND IMPACT OF THE STUDY: The need of a simple yet effective way of encapsulating plant growth promoting rhizobacteria is crucial to further improve their benefits to global sustainable agriculture practice. Effective encapsulation allows for protection, controlled release and function of the micro-organism, as well as providing a longer shelf life for the product. This research report offers an innovative yet simple way of encapsulating using double coating technology with environmentally friendly biopolymers that could degrade and provide nutrients when in soil. Importantly, the bioactivity of the bacteria is maintained upon encapsulation.
为快速增长的人口提供可持续的作物生产是农业部门当前面临的挑战之一。然而，农业中使用的许多化学药剂可能对人类、非目标生物和环境有害。植物促生根际细菌已证明在包括病害在内的各种胁迫条件下对促进植物生长和健康具有作用。不幸的是，由于温度和其他环境因素，细菌的活力会下降（巴珊等人，《植物与土壤》378: 1 - 33，2014）。将细菌封装到核壳生物聚合物中是克服这一问题的有前景的技术之一。本研究采用简单的双涂层生物聚合物技术对芽孢杆菌Bacillus salmalaya 139SI进行封装，该技术由糙米蛋白/海藻酸盐和pH值为4和6的0.5%低分子量壳聚糖组成。系统研究了生物聚合物与细菌质量比以及壳聚糖pH值对封装过程、封装后的芽孢杆菌B. salmalaya 139SI的物理化学、形态和生物活性特性的影响。基于对物理化学、形态和生物活性特性的分析，采用双涂层封装技术封装的芽孢杆菌B. salmalaya 139S1在冻干前后具有良好的活力，封装产率分别高达99.7%和89.3%。研究的意义和影响：需要一种简单而有效的方法来封装植物促生根际细菌，这对于进一步提高它们对全球可持续农业实践的益处至关重要。有效的封装能够保护微生物、实现其控释和功能，同时延长产品的保质期。本研究报告提供了一种创新且简单的双涂层技术封装方法，使用的是环境友好型生物聚合物，在土壤中会降解并提供养分。重要的是，封装后细菌的生物活性得以保持。
